Varus–valgus alignment in the progression of patellofemoral osteoarthritis

Abstract

Objective. To test the hypotheses that lateral patellofemoral (PF) osteoarthritis (OA) progression is more common than medial PF OA progression, that varus alignment increases the likelihood of medial PF OA progression, and that valgus alignment increases the likelihood of lateral PF OA progression.Methods. Patients with knee OA were recruited from the community. Inclusion criteria were definite osteophyte presence (i.e., Kellgren/Lawrence radiographic grade >2) in 1 or both knees and at least some difficulty with knee-requiring activity. Varus-valgus alignment (the angle formed by the intersection of the mechanical axes of the femur and tibia) was measured on a full-limb radiograph at baseline. To assess PF OA progression, weight-bearing skyline views of the PF compartment were obtained at baseline and at 18-month followup. Knees with the highest grade of PF narrowing at baseline were excluded from analysis. Logistic regression and generalized estimating equations were used; odds ratios (ORs) were adjusted for age, sex, and body mass index.Results. Lateral PF OA progression, which occurred in 120 (30%) of 397 knees, was more common than was medial PF OA progression, which occurred in 60 knees (15%). Varus (versus nonvarus) alignment increased the odds of PF OA progression isolated to the medial PF compartment (adjusted OR 1.85, 95% confidence interval [95% CI] 1.00-3.44). Valgus alignment increased the odds of PF OA progression isolated to the lateral compartment (adjusted OR 1.64, 95% CI 1.01-2.66).Conclusion. Lateral PF OA progression was more common than medial progression, and varus-valgus alignment influenced the likelihood of PF OA progression in a compartment-specific manner. Interventions that address the stress imposed by alignment on the PF compartments may delay PF OA progression and should be developed.Knee osteoarthritis (OA) is responsible for a substantial portion of the disability attributable to OA as a whole. Its prevalence increases dramatically with age. Knee OA is a leading cause of disability in older individuals (1); its impact is likely to increase, given the doubling of the population of individuals ages 65 years or older that is expected to occur in the next 30 years.Patellofemoral (PF) involvement in knee OA is relatively frequent and is associated with function limitation at least comparable with and perhaps exceeding the limitation associated with tibiofemoral OA (2). Despite this, natural history studies continue to emphasize the tibiofemoral compartments. Neither the natural history of PF OA nor risk factors for PF OA radiographic progression have been characterized. Knowledge of these factors will allow identification of the individuals in whom OA is most likely to worsen, and will support development of interventions to delay progression.Patellofemoral pathology (e.g., dislocation, lateral pressure syndrome) is more common on the lateral side of the PF joint, due to a lateral reaction force vector (3). The relatively lateral position of the tibial tubercle in full-knee extension...

Self‐reported knee and foot alignments in early adult life and risk of osteoarthritis

“…We did not find toe out to be protective against knee OA per se. Instead, we agree with one previous report that toe out may influence the distribution of OA in being protective against OA change (i.e., definite narrowing with osteophyte) in the medial patellofemoral compartment (30). This supports the hypothesis that possible strategies to reduce the incidence of OA from knee malalignment could include orthotic footwear (31) or the deliberate adaption of a toe-out foot alignment during gait (19,20).…”

“…Most previous studies have studied medial tibiofemoral compartment OA changes. However, patellofemoral OA is common (29,30) and medial or lateral progression has previously been linked with varus or valgus knee alignments, respectively (30). The mechanism hypothesized for was that changes in the Q-angle led to altered medial or lateral stresses on the patella (30).…”

Gender Differences in the Activity and Ratio of Vastus Medialis Oblique and Vastus Lateralis Muscles during Drop Landing

“…The weakness of quadriceps during climbing or descending stairs is a major cause of patellofemoral pain syndrome or osteoarthritis in the knee for women 8) . Especially, the syndrome appears more often among women who are afflicted with muscle weakness and muscle imbalance 9) .…”

Role of physical activity in knee osteoarthritis

“…Варусно-вальгустные деформации конечностей влияют на прогрессию соответствующей (медиаль ной или латеральной) области пателлофеморально го отдела [13]. Можно сделать практический вывод о том, что тренировки мышечных групп, укрепляю щих сустав, должны быть индивидуализированы с учетом его локальной биомеханики.…”